Touch input detection

ABSTRACT

Example implementations relate to touch input detection. In some examples, a computing device may include a touch sensitive interface, a processing resource, and instructions executable by the processor. The instructions may be executable by the processor to cause the processor to detect a period of inactivity of the touch-sensitive interface; activate a one-dimensional scan for a touch input on the touch-sensitive interface in response to detecting the period of inactivity; and activate a two-dimensional scan for a touch input on the touch sensitive interface in response to detecting the period of inactivity.

BACKGROUND

Computing devices are prevalent in the human environment. Computingdevices are relied on for work, entertainment, communication, and manyother purposes. Computing devices may utilize input interfaces totranslate user input into data and control signals to the computingdevice. For example, computing devices may include touch-sensitiveinterfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a computing device to perform touchinput detection consistent with the disclosure.

FIG. 2 illustrates an example of a touch-sensitive interface utilizing atwo-dimensional scan consistent with the disclosure.

FIG. 3 illustrates an example of a touch-sensitive interface utilizing aone-dimensional scan consistent with the disclosure.

FIG. 4 illustrates a diagram of an example of a processing resource anda non-transitory computer readable medium for touch input detectionconsistent with the disclosure.

FIG. 5 illustrates a flow diagram of a method for touch input detectionconsistent with the disclosure.

DETAILED DESCRIPTION

A computing device may include a processing resource such as electroniccircuitry to execute instructions stored on machine-readable medium toperform various operations. Computing devices may be static or mobile.Computing devices may include a smartphone, a gaming console, electronicvoting machines, point of sale systems, automatic teller machines, aninteractive display, an interactive whiteboard, a personal digitalassistant, an automated industrial appliance, a smart home controlsystem component, a smart television, a tablet, a laptop, alaptop-tablet hybrid, a handheld computer, a smart device, a desktopcomputer, etc.

A computing device may include an input interface. An input interfacemay include a device and/or a portion of a device that can receive userinput and translate the user input into data and control signals for acomputing device. For example, a computing device may include an inputinterface such as a physical keyboard with mechanically actuatedbuttons, a joystick able to be physically actuated into variousposition, and/or a physical pointing device such as a mouse or atrackball that are physically manipulated by a user.

In some examples, a computing device may include a touch-sensitiveinterface to accept user input. For example, the computing device mayinclude a touchscreen or touchpad. As used herein, a touch-sensitiveinterface may include an interface that receives input by detecting usermovement and/or user touch at or near the touch-sensitive interface. Thetouch sensitive interface stands in contrast to a mechanical inputinterface that relies on a user physically manipulating a device such asa keyboard button or a physical mouse. The touch-sensitive interfaceinstead may, for example, translate user touch and/or movement along atouch-sensitive region overlaid over a display. That is, atouch-sensitive interface may include a touchscreen style interface thatdetect and translate user inputs without the benefit of a mouse,trackball, joystick, or keyboard.

A touch-sensitive interface may include a touchscreen. A touch screenmay include an input and/or output device that may be layered on top ofan electronic visual display (e.g., monitor) of a computing device. Thetouch screen may detect user input as simple or multi-touch gestures bytouching on or near the screen with a stylus and/or one or more fingers.The touchscreen may facilitate a user to interact directly with what isdisplayed (e.g., icons on a graphical user interface (GUI) displayed bythe computing device, a virtual keyboard, GUI components of instructionsexecuting on the computing device, pictures, videos, etc.). An amount ofpower that a computing device consumes may be affected by the use of atouch-sensitive interface. Increased power consumption by a computingdevice may result in increased utility costs associated with operatingthe computing device and/or a decreased battery life for the computingdevice. A computing device utilizing a touch-sensitive interface mayconsume significantly more power than one that does not. For example, acomputing device utilizing a touch-sensitive interface may experiencetwenty-five percent less operating life from a same battery supply as acomputing device that is not utilizing a touch-sensitive interface. Theadditional battery consumption may lead some users to disable thetouch-sensitive interface altogether in an attempt to preserve batterylife.

In contrast, examples of the present disclosure may include computingdevices, methods, and machine-readable media to perform touch inputdetection consistent with the disclosure. The examples may provide apower savings to a computing device while retaining a functionality of atouch sensitive interface. For example, a device may include atouch-sensitive interface, a processor, and instructions executable bythe processor to cause the processor to perform operations. For example,the instructions may be executable by the processor to cause theprocessor to detect a period of inactivity of the touch-sensitiveinterface. The instructions may be executable by the processor to causethe processor to activate a one-dimensional scan for a touch input onthe touch-sensitive interface in response to detecting the period ofinactivity. The instructions may be executable by the processor to causethe processor to activate a two-dimensional scan for a touch input onthe touch sensitive interface in response to detecting the touch inputby the one-dimensional scan.

FIG. 1 illustrates an example of a computing device 100 perform touchinput detection consistent with the disclosure. The computing device 100may include a processing resource. The processing resource may includeelectronic circuitry within a computing device that executesinstructions. The processing resource may include a central processingunit (CPU), a microprocessor, and/or an application specific integratedcircuit (ASIC).

The computing device 100 may include an electronic visual display. Theelectronic visual display may include the electronic componentsassociated with generating an electronic image of a graphical userinterface (GUI). The electronic visual display may include, for example,an LCD panel with an LED backlight.

The computing device 100 may include a touch-sensitive interface 102.The touch-sensitive interface 102 may include a touchscreen layered overan electronic visual display. The touch-sensitive interface 102 mayinclude an optical touch-screen panel. The touch-sensitive interface 102may include a pane of transparent material which may be touched. A panemay include a sheet of material such as a sheet of glass. The pane maybe part of an electronic display. A first surface of the pane may faceaway from the display and/or toward a user. The first surface of thepane may appear as though it is an outermost surface of a display. Thefirst surface of the pane may be the surface of the pane that isaccessible to be touched by a user.

A touch-sensitive interface 102 may utilize diverse mechanisms to detectuser input. For example, a touch-sensitive interface 102 may utilize aresistive panel. The resistive panel may be overlaid over a display. Theresistive panel may comprise several layers. Two of the layers mayinclude thin, transparent, electrically resistive layers separated by athin space. The two layers may face each other with a gap between. Thetop layer that is physically touched by a user may have a coating on theunderside of its surface. Just beneath the top layer may be a similarresistive layer on top of its substrate. One layer may have conductiveconnections along its sides and the other along a top and bottom. Avoltage may be applied to one layer and sensed by the other. When anobject such as a fingertip presses down onto the outer surface, the twolayers touch to become connected at that point and the panel may thenbehave as a pair of voltage dividers at the contact point one axis at atime. By switching between each layer, the position of a pressure on thescreen can be read. The position of the touch event may be sent to acontroller for processing

In another example, a touch-sensitive interface 102 may utilize asurface acoustic wave over a touchscreen panel. For example, anultrasonic wave may be passed over the panel and when the panel istouched by, for example, a fingertip the wave may be absorbed. Thechange in the ultrasonic wave may register the position of the touchevent and send the information to a controller for processing.

In another example, a touch-sensitive interface 102 may utilize acapacitive touchscreen panel. A capacitive touchscreen panel may consistof an insulator such as glass, coated with a transparent conductor suchas indium tin oxide (ITO). As the human body is also an electricalconductor, touching the surface of the screen may result in a distortionof the screens electrostatic field. Measureable as a change incapacitance. Various technologies may be used to determine the locationof the touch. The location may then be sent to a controller forprocessing.

In yet another example, the touch-sensitive interface 102 may utilize aprojected capacitive touch (PCT or PCAP) panel. A PCT touchscreen panelmay include a matrix of rows and columns of conductive material layeredon sheets of glass. Voltage applied to this grid may create asubstantially uniform electrostatic field which can be measured. When aconductive object, such as a finger, comes into contact with a PCTtouchscreen panel it may distort the local electrostatic field at thatcontact point. This distortion may be measureable as a change incapacitance. If a finger bridges the gap between two of the “tracks”,the charge field may be further interrupted and detected by acontroller. The capacitance may be changed and measured at everyindividual point on the grid (e.g., intersection).

In another example, the touch-sensitive interface 102 may utilize anoptical touchscreen panel. The optical touch-screen panel may include anarray of light emitting diode (LED) photoemitter and photodetectorpairs. The photoemitters and photodetectors may emit and/or detect beamsof infrared light and/or beams of light of from other portions of theelectromagnetic spectrum, both visible and invisible to the human eye.The photoemitter and photodetector pairs may be arranged around theedges of a touchscreen panel and/or display. The photoemitter andphotodetector pairs may be arranged around the edges of a touchscreenpanel and/or display such that they form an X-Y arrayed grid with LEDbeams crossing each other overlaying the touchscreen in a plane parallelto the plane of the touchable surface of the touchscreen. When anobject, such as a finger, passes between a photoemitter and aphotodetector pair, the beam path between the two may be interrupted.The interruption of the beam may be detected by the photodetector andthe location may then be sent to a controller for processing. Since thephotoemitter and photodetector pairs are arranged such that the beamsare arrayed in an X-Y grid over the touchscreen panel and/or display, aninterruption may be detected by a first photoemitter and photodetectorpair arrayed in an X direction and a second photoemitter andphotodetector pair arrayed perpendicular to the first pair in a Ydirection and an X-Y coordinate of the location of the touch on thetouchscreen and/or display may be identified.

The touch-sensitive interface 102 may include an input sensor pair. Forexample, the touch-sensitive interface 102 may include an LEDphotoemitter and photodetector pair. The LED photoemitter may utilize anLED to emit a beam of light. A photodetector may be paired with thephotoemitter. The photodetector may be aligned in the beam path of thebeam emitted by the photoemitter. The photodetector may detect thearrival and/or interruption of the arrival of the beam from thephotoemitter at the photodetector. As such, the photodetector may beable to detect the presence of an object, such as a finger, in the beampath between the pair. A plurality of photoemitter and photodetectorpairs may be arranged along the edges of the pane. For example, eachphotoemitter and photodetector of a pair may be arranged on opposingedges of the pane such that the beam path between the pair traverses aportion of the first surface of the pane. The plurality of photoemitterand photodetector pairs may be arranged about the edges of the pane suchthat they collectively form an X-Y grid of intersecting beam paths overthe first surface of the pane. That is, a first portion of the pluralityof photoemitter and photodetector pairs may be arrayed along a firstaxis (e.g., X-axis) of a coordinate grid laid over the first face of thepane and a second portion of the plurality of photoemitter andphotodetector pairs may be arrayed along a second axis (e.g., Y-axis),substantially perpendicular to the first axis, of a coordinate gridoverlaid on the first face of the pane.

With the above described example arrangement of photoemitter andphotodetector pairs, an object such as a finger placed on the first panemay interrupt a beam path of a photoemitter and photodetector pairaligned along an X-axis and interrupt a beam path of a photoemitter andphotodetector pair aligned along a Y-axis. As such, a touch inputdetected by the interruption of the photoemitter and photodetectorpairs' beam paths may be associated with an X-Y coordinate on the X-Ygrid over the first surface of the pane.

The touch-sensitive interface 102 may detect touch inputs as describedabove. For example, the touch sensitive interface 102 may detect thecontact and/or movement of an object with the first surface of the pane.The touch input detected by the touch-sensitive interface 102 may besent to a controller. The controller may convert the touch input data tointo data and control signals for a computing device.

The computing device 100 may include a computer readable media. Thecomputer readable media may include a non-transitory computer readablemedia. The non-transitory computer readable media may include any typeof volatile or non-volatile memory or storage, such as random accessmemory (RAM), flash memory, read-only memory (ROM), storage volumes, ahard disk, or a combination thereof.

The non-transitory computer readable media may include instructionsstored thereon. The instructions may be executable by the processingresource to cause the processing resource to perform a computingoperation.

In addition to, or in place of, the execution of executableinstructions, various examples of the present disclosure can beperformed via one or more devices (e.g., one or more controllers) havinglogic. As used herein, “logic” is an alternative or additionalprocessing resource to execute the actions and/or functions, etc.,described herein, which includes hardware (e.g., various forms oftransistor logic, application specific integrated circuits (ASICs),etc.), as opposed to computer executable instructions (e.g., software,firmware, etc.) stored in memory and executable by a processor. It ispresumed that logic similarly executes instructions for purposes of theembodiments of the present disclosure.

The computing device 100 may include instructions executable by theprocessor to cause the processor to detect a period of inactivity of thetouch-sensitive interface 102. Detecting a period of inactivity mayinclude determining that no touch input has been detected by thetouch-sensitive interface for a period of time. Detecting a period ofinactivity may include determining that a scan for a touch input did notdetect a touch input for a period time. Detecting a period of inactivitymay include determining that a two-dimensional scan for a touch inputover a period of time did not result in a touch input for a period oftime.

A two-dimensional scan may include periodically outputting and/oremitting a beam of light from a photoemitter in a beam path to a pairedphotodetector along a first axis and emitting a beam of light from aphotoemitter in a beam path to a paired photodetector along a secondaxis substantially perpendicular to the first axis. That is, atwo-dimensional scan may include periodically outputting and/or emittinga beam of light from a photoemitter in a beam path to a pairedphotodetector along an X-axis and emitting a beam of light from aphotoemitter in a beam path to a paired photodetector along a Y-axis.The two-dimensional scan may include utilizing a plurality photoemitterand photo detector pairs arrayed in an X-Y grid over a first surface ofthe pane to detect a touch input at the first surface of the pane.

The two-dimensional scan may include an active scanning process ofoutputting and/or emitting a beam of light from a photoemitter in a beampath to a paired photodetector along an X-axis and emitting a beam oflight from a photoemitter in a beam path to a paired photodetector alonga Y-axis at a first scan rate. A scan rate may refer to the periodicityat which the beams of light are emitted and/or a periodicity at whichphotodetectors detect the beam. That is, a scan rate may refer to a rateand/or frequency of outputting and/or emitting a beam of light from aphotoemitter in a beam path to a paired photodetector along an X-axisand emitting a beam of light from a photoemitter in a beam path to apaired photodetector along a Y-axis. Stated differently, the scan ratemay refer to the frequency with which photodetectors and photoemittersattempt to detect touch inputs in the X-axis and Y-axis planes. A higherscan rate may correspond to a more frequent emission of a beam of lightfrom the photoemitters, a more responsive and rapid detection of a touchinput, a higher likelihood of detecting a touch input over a period oftime, and a higher rate of power consumption associated with the morefrequent emission of the beams of light.

The two-dimensional scan may include an active scanning process ofoutputting and/or emitting a beam of light from a photoemitter in a beampath to a paired photodetector along an X-axis and emitting a beam oflight from a photoemitter in a beam path to a paired photodetector alonga Y-axis at a first scan resolution. A scan resolution may refer to acharacteristic of the light beams employed in the two-dimensional scan.For example, a scan resolution can refer to an amount of the pluralityof photoemitters and photodetector pairs that are outputting and/oremitting beams of light during a portion of the two-dimensional scan.The scan resolution may also refer to the width of, pattern of, and/orintensity of a beam emitted by the plurality of photoemitters andphotodetector pairs. A higher scan resolution may refer to theutilization of relatively more of the plurality of photoemitters andphotodetector pairs during a two-dimensional scan. A higher scanresolution may correspond to a more responsive and rapid detection of atouch input, a higher likelihood of detecting a touch input over aperiod of time, a more precise identification of the X-Y coordinates ofa touch input, and a higher rate of power consumption associated withthe greater amount of light beam emitting photoemitter and photodetectorpairs.

Detecting a period of inactivity may include determining that thetwo-dimensional scan for a touch input at a first scan rate and at afirst scan resolution over a period of time did not result in a touchinput for a period of time. For example, the computing device 100 mayperform a two-dimensional scan utilizing the touch-sensitive interface102 at a first rate and a first resolution. The computing device 100 maydetect that no touch input was detected for a period of time such asthree minutes of two-dimensional scanning. That is, the computing device100 may determine that the touch-sensitive interface was not touched bya user during the preceding three minutes of two-dimensional scanning ofthe touch-sensitive interface 102.

The computing device 100 may include instructions executable by theprocessor to cause the processor to activate a one-dimensional scan fora touch input on the touch-sensitive interface 102. The computing device100 may activate a one-dimensional scan of a touch input in response todetecting the period of inactivity. For example, the computing device100 may determine that the touch-sensitive interface was not touched bya user during a preceding period of time of two-dimensional scanning ofthe touch-sensitive interface 102. In response to determining that notouch input was detected during the time period of two-dimensionalscanning the computing device 100 may switch the computing device 100into a detection mode. The detection may be a power saving mode. Thedetection mode may offer a savings over the two-dimensional scanoperations by activating operation of the touch-sensitive interface 102with a one-dimensional scan.

Activating a one-dimensional scan may include utilizing active scanningprocess of outputting and/or emitting a beam of light from aphotoemitter in a beam path to a paired photodetector along one of anX-axis or a Y-axis. In contrast to the two-dimensional scan, the onedimensional scan may include scanning along on dimension or axis of thetouch-sensitive interface 102. The computing device 100 may refrain fromoutputting and/or emitting a beam of light from a photoemitter andphotodetector pair that is aligned along a second axis substantiallyperpendicular to the axis of the beam path of the photoemitter andphotodetector pair that is being utilized in the one-dimensional scan.Since the one-dimensional scan may emit and/or detect beams of lightalong one axis of an X-Y grid and not the other, the controller and/orcomputing device 100 may receive a coordinate and/or coordinates of oneaxis and not the other. In an example where the one-dimensional scan isperformed along the X-axis and not the Y-axis, an X-axis coordinate orcoordinates of the touch input may be detected and or sent to thecontroller, but not a Y-axis coordinate since the Y-axis photoemitterand photodetector pairs are not operated and the Y-axis coordinate datais not collected in such an example. In another example, theone-dimensional scan may be performed along the Y-axis and not theX-axis

The computing device 100 may select the portion of the plurality of thephotoemitter and photodetector pairs that may be utilized in aone-dimensional scan. For example, the computing device 100 may selectthe portion of the plurality of the photoemitter and photodetector pairsthat are aligned along the X-axis for utilization and exclude thosealigned along the Y-axis from utilization in the one dimensional scan.Alternatively, the computing device 100 may select the portion of theplurality of the photoemitter and photodetector pairs that are alignedalong the Y-axis for utilization and exclude those aligned along theX-axis from utilization in the one dimensional scan.

The computing device 100 may select an axis along which to scan to theexclusion of other axes resulting in a one-dimensional one-axis scan.The selection of the portion of the plurality of the photoemitter andphotodetector pairs and/or the axis along which to scan may be based oncharacteristics of the touch-sensitive interface 102. For example, theselection of the portion of the plurality of the photoemitter andphotodetector pairs and/or the axis along which to scan may be based onthe dimensions of the touch-sensitive interface 102 and/or the amount ofphotoemitter and photodetector pairs associated with each axis of thetouch-sensitive interface. For example, the computing device may selectto perform the one-dimensional scan along the Y-axis. In such anexample, the one-dimensional scan along the Y-axis may utilize thephotoemitter and photodetector pairs aligned along opposing edges of thetouch-sensitive interface 102. The photoemitter and photodetector pairsaligned along opposing edges of the touch-sensitive interface 102 mayhave beam paths aligned along a Y-axis. The selection of thesephotoemitter and photodetector pairs may be based on a determinationthat the length of the opposing edges of the touch-sensitive interface102 that the photoemitter and photodetector pairs are arranged on isless than the same dimension of the perpendicular top and bottom edgesof the touch-sensitive interface 102. The perpendicular top and bottomedges of the touch-sensitive interface 102 may be the edges along whichX-axis aligned photoemitter and photodetector pairs are present.

Similarly, the computing device 100 may select to perform theone-dimensional scan along the Y-axis. In such an example, theone-dimensional scan along the Y-axis may utilize the photoemitter andphotodetector pairs aligned on opposing edges of the touch-sensitiveinterface 102. The photoemitter and photodetector pairs aligned alongopposing edges of the touch-sensitive interface 102 may have beam pathsaligned along a Y-axis. The selection of these photoemitter andphotodetector pairs may be based on a determination that fewerphotoemitter and photodetector pairs are present along the opposingedges than are present along the perpendicular top and bottom edges ofthe touch-sensitive interface 102. The perpendicular top and bottomedges of the touch-sensitive interface 102 may be the edges along whichX-axis aligned photoemitter and photodetector pairs are present.

The examples of one-dimensional scans described above may produce apower saving over the two-dimensional scan for the computing device 100and may even extend battery life for the computing device 100 inexamples where the computing device relies on a battery for power. Forexample, a one-dimensional scan of the touch sensitive interface 102 maylimit power utilization to powering the photoemitter and photodetectorpairs that are aligned along a single axis of the touch-sensitiveinterface 102. For example, the one-dimensional scan may produce a powersavings by operating half or fewer of the photoemitter and photodetectorpairs available for utilization in an active scan.

While the rate and/or resolution of the two-dimensional scan may beadjusted downward in order to conserve power, utilizing theone-dimensional scan may produce a greater power savings and retain agreater responsiveness and touch input detection rate than the adjustedtwo-dimensional scan. For example, while the rate and resolution of thetwo-dimensional scan may be revised lower, the two-dimensional scanstill involves the use of more photoemitter and photodetector pairsoverall since the two-dimensional scan is attempting to identify anX-axis coordinate and a Y-axis coordinate of a touch input. In contrast,the one-dimensional scan forgoes even attempting to collect one entireaxis worth of information. Further, a decrease in the rate or resolutionof the two-dimension scan may decrease the coverage and/or frequency ofcoverage for detection of a touch-input over the touch-sensitiveinterface 102 since the photoemitter and photodetector pairs may beutilized with less frequency and with less coverage. In contrast,substantially the entire touch-sensitive interface 102 may remain underscan for a touch input during the one-dimensional scan, albeit in asingle axis.

The one-dimensional scan may be performed at a second scan rate and/or asecond scan resolution. The second scan rate and the second scanresolution of the one-dimensional scan may be the same as or differentthan the first scan rate and the first scan resolution of atwo-dimensional scan. In some examples, the second scan rate and/or thesecond scan resolution of the one-dimensional scan may be lower than thefirst scan resolution and/or the first scan rate of the two-dimensionalscan. In some examples, a first optical beam pattern may be utilized bythe photoemitters during the one-dimensional scan and a second opticalbeam pattern may be utilized by the photoemitters during thetwo-dimensional scan. The first and/or the second scan resolution may bea configurable setting available for manipulation by a user of thecomputing device 100.

As described above, when the computing device 100 is utilizing aone-dimensional scan a coordinate pair, such as an X-Y coordinate pair,will not be detected and/or collected, rather data from one axis may bedetected and/or collected. For example, when the one-dimensional scanutilizes photoemitter and photodetector pairs aligned along a Y-axis andnot those aligned along an X-axis, the computing device 100 may detectand/or collect data associated with the touch input from thephotoemitter and photodetector pairs aligned along a Y-axis but notthose aligned along an X-axis. As such, the touch input may be detectedas having occurred at the touch-sensitive interface 102 and/or anidentifier of a location of the touch on the touch-sensitive interface102 with respect to a single axis and not another of the touch sensitiveinterface 102.

A computing device 100 may not be able to identify a precise location ofthe touch-sensitive user interface 102 where a touch input was detectedutilizing the one-dimensional scan. Therefore, the computing device 100may not be able to identify precisely to which portion of the graphicaluser interface or computing action a touch input refers. Instead, atouch input detected by a one-dimensional scan may operate as aninstruction to the computing device to activate a two-dimensional scanmode.

The computing device 100 may include instructions executable by theprocessor to cause the processor to activate a two-dimensional scan fora touch input on the touch sensitive interface 102. The activation ofthe two-dimensional scan may be in response to a detection of a touchinput by the one dimensional scan. Activating the two-dimensional scanmay include initiating an active scanning process including outputtingand/or emitting a beam of light from a photoemitter in a beam path to apaired photodetector along an X-axis and emitting a beam of light from aphotoemitter in a beam path to a paired photodetector along a Y-axis atthe first scan rate and the first scan resolution.

The switch from the one-dimensional scan to the two-dimensional scan mayoccur rapidly. For example, the switch from the one-dimensional scan tothe two-dimensional scan may occur within fifteen milliseconds.Therefore, a touch input that is detected with a one dimensional scanwill most likely still be occurring after the computing device 100 hasswitched to performing a two-dimensional scan. The computing device 100may then rescan and/or detect the same touch input that triggered theswitch to a two-dimensional scan. Whereas the one-dimensional scan ofthe touch input may only detect the location of the touch input relativeto a single axis, the two-dimensional scan may detect both the X-axisand Y-axis position of the touch input. Therefore, the computing device100 may identify a precise location of the touch-sensitive interface 102where the touch input was detected utilizing the two-dimensional scan.The computing device 100 may identify the precise portion of thegraphical user interface or computing action of the touch input duringthe two-dimensional scan.

Since the one-dimensional scan utilizes less power than thetwo-dimensional scan, the computing device 100 may conserve power byoperating the touch-sensitive interface 102 utilizing theone-dimensional scan and switching to the higher power consumingtwo-dimensional scan once a touch input has been detected. Moreover,since the switch from the one-dimensional scan to the two-dimensionalscan occurs rapidly enough to rescan the touch input in thetwo-dimensional mode and collect the full X-Y coordinate positional datafor the touch input to be utilized by the computing device 100. That is,despite experiencing the power savings associated with operating thetouch-sensitive interface 102 utilizing a one-dimensional scan there isno loss of resolution in detecting the touch inputs detectable by auser.

As described above, the computing device 100 may, after activating thetwo-dimensional scan, begin monitoring a time that has elapsed from thelast touch input detected by the two-dimensional scan. As soon as apreset amount of time has elapsed since the last touch input wasdetected by the two-dimensional scan, the computing device 100 mayswitch back into the one-dimensional scan in order to preserve battery.The elapsed time since the last touch input may be reset every time anew touch input is detected by the two-dimensional scan. Operating thetouch-sensitive interface 102 utilizing a one-dimensional scan mayproduce a power savings of approximately fifty percent, taking powerconsumption from 60-100 milliwatts utilizing a two-dimensional scan to30 milliwatts utilizing a one-dimensional scan.

FIG. 2 illustrates a touch-sensitive interface 202 utilizing atwo-dimensional scan consistent with the disclosure. The touch-touchsensitive interface may include a plurality of LED photoemitters 204-1 .. . 204-N and 208-1 . . . 208-N. The touch-sensitive interface 202 mayinclude a plurality of photodetectors 206-1 . . . 206-N and 210-1 . . .210-N. The LED photoemitters 204-1 . . . 204-N and 208-1 . . . 208-N andthe plurality of photodetectors 206-1 . . . 206-N and 210-1 . . . 210-Nmay be arranged around the outside edge of the touch-sensitive interface202. The LED photoemitters 204-1 . . . 204-N and 208-1 . . . 208-N andthe plurality of photodetectors 206-1 . . . 206-N and 210-1 . . . 210-Nmay be arranged in pairs of a photoemitter (e.g., 208-1) and aphotodetector (e.g., 210-1) positioned across from one another relativeto the touch-sensitive interface 202 such that a beam of light(illustrated as a solid line between the two) emitted from thephotoemitter traverses the face of the touch-sensitive interface 202 andis detected by its paired photodetector.

A first portion of the photoemitter and photodetector pairs 204-1 . . .204-N and 206-1 . . . 206-N may be arranged such that the light beamemitted from a photoemitter to its paired photodetector is aligned alonga first axis 212 (e.g., X-axis) relative to the face of thetouch-sensitive interface 202. A second portion of the photoemitter andphotodetector pairs 208-1 . . . 208-N and 210-1 . . . 210-N may bearranged such that the light beam emitted from a photoemitter to itspaired photodetector is aligned along a second axis 214 (e.g., Y-axis)relative to the face of the touch-sensitive interface 202.

Utilizing a two-dimensional scan may include utilizing the first portionof the photoemitter and photodetector pairs 204-1 . . . 204-N and 206-1. . . 206-N and the second portion of the photoemitter and photodetectorpairs 208-1 . . . 208-N and 210-1 . . . 210-N to detect a touch input onthe touch-sensitive interface 202 interrupting one of the light beamsbeing transmitted between the pairs. The touch input may be identifiedalong with a coordinate corresponding to the first axis 212 and acoordinate corresponding to the second axis 214. For example, the touchinput may be identified along with an X-Y coordinate pair identifyingthe location of the touch input on the touch-sensitive interface 202.The two-dimensional scan may be an active scan to detect a touch inpututilizing photoemitter and photodetector pairs scanning fromsubstantially perpendicular edges to form a detection grid across theface of the touch-sensitive interface.

FIG. 3 illustrates a touch-sensitive interface 302 utilizing aone-dimensional scan consistent with the disclosure. The touch-touchsensitive interface may include a plurality of LED photoemitters 304-1 .. . 304-N and 308-1 . . . 308-N. The touch-sensitive interface 302 mayinclude a plurality of photodetectors 306-1 . . . 306-N and 310-1 . . .310-N. The LED photoemitters 304-1 . . . 304-N and 308-1 . . . 308-N andthe plurality of photodetectors 306-1 . . . 306-N and 310-1 . . . 310-Nmay be arranged around the outside edge of the touch-sensitive interface302. The LED photoemitters 304-1 . . . 304-N and 308-1 . . . 308-N andthe plurality of photodetectors 306-1 . . . 306-N and 310-1 . . . 310-Nmay be arranged in pairs of a photoemitter (e.g., 308-1) and aphotodetector (e.g., 310-1) positioned across from one another relativeto the touch-sensitive interface 302 such that a beam of light(illustrated as a solid line between the two) emitted from thephotoemitter traverses the face of the touch-sensitive interface 302 andis detected by its paired photodetector.

A first portion of the photoemitter and photodetector pairs 304-1 . . .304-N and 306-1 . . . 306-N may be arranged such that the light beamemitted from a photoemitter to its paired photodetector is aligned alonga first axis 312 (e.g., X-axis) relative to the face of thetouch-sensitive interface 302. A second portion of the photoemitter andphotodetector pairs 308-1 . . . 308-N and 310-1 . . . 310-N may bearranged such that the light beam emitted from a photoemitter to itspaired photodetector is aligned along a second axis 314 (e.g., Y-axis)relative to the face of the touch-sensitive interface 302.

Utilizing a one-dimensional scan may include utilizing the first portionof the photoemitter and photodetector pairs 304-1 . . . 304-N and 306-1. . . 306-N, but not the second portion of the photoemitter andphotodetector pairs 308-1 . . . 308-N and 310-1 . . . 310-N, to detect atouch input on the touch-sensitive interface 302 interrupting one of thelight beams being transmitted between the pairs. The touch input may beidentified along with a coordinate corresponding to the first axis 312,but not a coordinate corresponding to the second axis 314. For example,the touch input may be identified along with an X coordinate identifierassociated with the location of the touch input on the touch-sensitiveinterface 302, but not a Y coordinate identifier since the portion ofthe photoemitter and photodetector pairs 308-1 . . . 308-N and 310-1 . .. 310-N that collect Y coordinate identifiers are not utilized in theillustrated examples of a one-dimensional scan.

FIG. 4 illustrates a diagram 420 of an example of a processing resource422 and a non-transitory machine readable medium 424 to perform touchinput detection consistent with the disclosure. A memory resource, suchas the non-transitory machine readable medium 424, may be used to storeinstructions (e.g., 426, 428, 430) executed by the processing resource422 to perform the operations as described herein. A processing resource422 may execute the instructions stored on the non-transitory machinereadable medium 424. The non-transitory machine readable medium 424 maybe any type of volatile or non-volatile memory or storage, such asrandom access memory (RAM), flash memory, read-only memory (ROM),storage volumes, a hard disk, or a combination thereof.

The example medium 424 may store instructions 426 executable by theprocessing resource 422 to monitor a touch-sensitive interface for anoccurrence of a touch input. Monitoring a touch-sensitive interface mayinclude monitoring the surface of a touch-sensitive interface usingutilizing an optical scan of the surface and detecting a touch input bydetecting an interruption in the beam path of the optical components.

Monitoring the touch-sensitive interface for the occurrence of a touchinput may include monitoring the touch-sensitive interface utilizing atwo-dimensional scan of the touch-sensitive interface. Thetwo-dimensional scan may be performed at a first scan rate and at afirst scan resolution. Performing the two-dimensional scan may includescanning, using a beam of light transmitted between LED photoemittersand photodetectors, the touch-sensitive interface along an x-axis andalong a y-axis perpendicular to the x-axis. The two-dimensional scan maybe utilized to detect the occurrence of a touch input and/or todetermine an X-Y coordinate of the touch input occurrence on a virtualX-Y grid overlaying the touch-sensitive interface and corresponding toX-axis aligned and Y-axis aligned LED photoemitters and photodetectors.

The example medium 424 may store instructions 428 executable by theprocessing resource 422 to monitor the touch-sensitive interface for theoccurrence of the touch input by performing a one-dimensional scan ofthe touch-sensitive input interface. The one-dimensional scan may beperformed at a second scan rate and a second resolution. The second scanrate and/or the second scan resolution may be lower than the first scanrate and the first scan resolution associated with the two-dimensionalscan.

Changing from monitoring the touch-sensitive interface with atwo-dimensional scan to monitoring the touch-sensitive interface with aone-dimensional scan may be performed in response to a determinationthat no touch input occurrence was detected with the two-dimensionalscan. For example, changing from monitoring the touch-sensitiveinterface with a two-dimensional scan to monitoring the touch-sensitiveinterface with a one-dimensional scan may be performed in response to adetermination that no touch input occurrence was detected by thetwo-dimensional scan within a period of time of utilizing thetwo-dimensional scan. In this manner, the default may be to initiallydetect touch input occurrences with the one-dimensional scan to reducepower consumption. The touch-sensitive interface may continue to utilizethe two-dimensional scan in circumstances where touch inputs occurrencesare substantially continuously detected in the two-dimensional scanmode.

Performing the one-dimensional scan may include scanning, using a beamof light transmitted between LED photoemitters and photodetectors, thetouch-sensitive interface along a single one of the X-axis and theY-axis without determining the X-Y coordinate of the touch inputoccurrence. The one-dimensional scan may be utilized to detect theoccurrence of a touch input and/or to determine a single one of an Xcoordinate or a Y coordinate of the touch input occurrence on a virtualX-Y grid overlaying the touch-sensitive interface and corresponding toX-axis aligned and Y-axis aligned LED photoemitters and photodetectors.

The example medium 424 may store instructions 430 executable by theprocessing resource 422 to switch back from monitoring thetouch-sensitive interface by utilizing a one-dimensional scan tomonitoring the touch-sensitive interface by utilizing thetwo-dimensional scan. The two-dimensional scan may, again, be performedthe first scan rate and the first scan resolution.

The switch back to the two-dimensional scan may be performed responsiveto detecting a touch input occurrence utilizing the one-dimensionalscan. That is, the touch-sensitive interface may operate in theone-dimensional scan mode until a touch input is detected triggering theswitch back to the two-dimensional mode. The detection of a touch inputoccurrence in the one-dimensional scan mode may not identify the X-Ycoordinates of the touch input since data for one of the coordinates wasnot collected in the scan. As such, the detection of a touch inputoccurrence in the one-dimensional scan mode may not be utilized by acomputing device to position a cursor or pointer or to perform anoperation visible on the displayed GUI, but may be utilized strictly totrigger the switch back to the two-dimensional scan. The switch to thetwo-dimensional scan may occur in fewer than fifteen milliseconds. As aresult, the touch input occurrence will likely still be present at thetouch-sensitive interface upon initiation of a two-dimensional scan. Thefollow up two dimensional scan of the same touch input occurrence maycollect the multi-axis coordinates of the touch input that will then beutilized to position a cursor or pointer or to perform an operationvisible on the displayed GUI.

Subsequent to the switch back to monitoring the touch-sensitiveinterface by performing the two-dimensional scan, a timer may bestarted. The purpose of the time may be to monitor the time that haselapsed since the last intervening touch input occurrence detected bythe two-dimensional scan. The timer may count down or up to a presettime limit. The expiration of the timer without a two-dimensional scandetection of an intervening touch input occurrence may trigger a switchback to monitoring the touch-sensitive interface utilizing theone-dimensional scan. The duration of the time may be a user-adjustablesetting. For example, a menu and/or setting option for thetouch-sensitive interface ay be accessible that allows a user to adjustthe amount of time that is allowed to lapse during a two-dimensionalscan mode before a switch to a one-dimensional scan mode is triggered.The menu and/or setting option may provide information regarding thepower savings and/or battery life extension associated with eachadjustment to the timer. Additionally, the timer may be adjusted basedon user selectable and/or preconfigured power saving modes that may alsocontrol settings such as backlight brightness, LCD panel activity, sleepmodes, etc.

FIG. 5 illustrates a flow diagram of an example of a method 540 toperform touch input detection consistent with the disclosure. At 542,the method 540 may include detecting a touch input at a touch-sensitiveinterface. The touch input may be detected utilizing a two-dimensionalscan of the touch-sensitive interface. A two-dimensional scan of thetouch-sensitive interface may include a multi-axis determination of thelocation of a touch input at a touch-sensitive interface. That is, thetwo-dimensional scan of the touch-sensitive interface may utilize touchinput detectors that are arrayed around the touch sensitive interfacesuch that touch input detectors with perpendicular detection areas maydetect a touch event from multiple angles to identify the location ofthe touch input on the touch-sensitive interface. The two-dimensionalscan may be performed at a first scan rate and at a first scanresolution.

At 544, the method 540 may include monitoring, utilizing thetwo-dimensional scan, the touch-sensitive interface for an interveningoccurrence of a touch input over a length of time. The touch inputoccurrence may be intervening in the sense that it occurs between themost recent detected occurrence detected by the two-dimensional scan andthe expiration of the length of time.

The length of time for monitoring utilizing the two-dimensional scan maybe reset in response to detecting an intervening occurrence of a touchinput within the length of time. That is, the length of time may beallowed to completely elapse without an intervening occurrence of atouch input before the switch to utilizing a one-dimensional scan. Witheach intervening occurrence of a touch input the length of time is notpaused or allowed to continue, but rather it resets to its originalvalue.

At 546, the method 540 may include switching from monitoring thetouch-sensitive interface for an additional occurrence of a touch inputby utilizing a two-dimensional scan to monitoring the touch sensitiveinterface utilizing a one-dimensional scan. Switching to monitoring thetouch-sensitive interface utilizing a one-dimensional scan may beperformed in response to a determination that no intervening occurrencea touch input was detected over the length of time of two-dimensionalscanning described above. The two dimensional scan may be performed at asecond scan rate and at a second scan resolution which is lower than thefirst scan rate and first scan resolution associated with thetwo-dimensional scan. That is, a computing device may switch to aone-dimensional scan of a touch-sensitive interface in the absence ofdetected touch inputs during the two-dimensional scan.

The method 540 may include switching back to monitoring thetouch-sensitive interface utilizing the two-dimensional scan in responseto detecting the additional occurrence. That is, if an additional touchinput is detected during the one-dimensional scan, the computing devicemay revert back to utilizing the two dimensional scan of thetouch-sensitive interface. Since the one-dimensional scan may notidentify a location (e.g., identifiable with X-Y coordinates) of thetouch input since less than all the data involved with making such adetermination is collected, the computing device may rescan theadditional occurrence utilizing a two-dimensional scan. Thetwo-dimensional scan may identify the location of the additional touchinput and the operations associated with the touch input and its X-Ylocation may be executed at that point by the computing device.

In the foregoing detailed description of the disclosure, reference ismade to the accompanying drawings that form a part hereof, and in whichis shown by way of illustration how examples of the disclosure may bepracticed. These examples are described in sufficient detail to enablethose of ordinary skill in the art to practice the examples of thisdisclosure, and it is to be understood that other examples may beutilized and that process, electrical, and/or structural changes may bemade without departing from the scope of the disclosure. A “pluralityof” is intended to refer to more than one of such things.

The figures herein follow a numbering convention in which the firstdigit corresponds to the drawing figure number and the remaining digitsidentify an element or component in the drawing. For example, referencenumeral 102 may refer to element “02” in FIG. 1 and an analogous elementmay be identified by reference numeral 202 in FIG. 2. Elements shown inthe various figures herein can be added, exchanged, and/or eliminated soas to provide a number of additional examples of the disclosure. As usedherein, the designator “N”, particularly with respect to referencenumerals in the drawings, indicates that a plurality of the particularfeature so designated can be included with examples of the disclosure.The designators can represent the same or different numbers of theparticular features. In addition, the proportion and the relative scaleof the elements provided in the figures are intended to illustrate theexamples of the disclosure, and should not be taken in a limiting sense.Further, as used herein, “a”, “a number of”, and/or “a plurality of” anelement and/or feature can refer to one or more of such elements and/orfeatures.

What is claimed:
 1. A computing device comprising: a touch-sensitiveinterface; a plurality of photoemitter and photodetector pairs arrangedaround edges of the touch-sensitive interface such that the plurality ofphotoemitter and photodetector pairs form a virtual X-Y arrayed gridoverlaying the touch-sensitive interface; a processing resource; andinstructions executable by the processor to cause the processor to:detect a period of inactivity of the touch-sensitive interface; activatea one-dimensional scan using a particular portion of the plurality ofphotoemitter and photodetector pairs for a touch input on thetouch-sensitive interface using a first optical beam pattern in responseto detecting the period of inactivity; detect an occurrence of the touchinput and determine an X coordinate or a Y coordinate of the touch inputoccurrence on the virtual X-Y arrayed grid overlaying thetouch-sensitive interface; and activate a two-dimensional scan for thetouch input on the touch sensitive interface using a second optical beampattern different than the first optical beam pattern in response todetecting the occurrence of the touch input by the one-dimensional scan;collect multi-axis coordinates of the touch input during thetwo-dimensional scan; and utilize the multi-axis coordinates to performan operation visible on an associated graphical user interface.
 2. Thedevice of claim 1, wherein the touch-sensitive interface is atouchscreen layered on an electronic visual display.
 3. The device ofclaim 1, including instructions executable by the processor to cause theprocessor to perform the one-dimensional scan at a lower scan rate thana scan rate of the two-dimensional scan.
 4. The device of claim 1,including instructions executable by the processor to cause theprocessor to perform the one-dimensional scan at a lower scan resolutionthan a scan resolution of the two-dimensional scan.
 5. The device ofclaim 1, wherein the touch-sensitive interface utilizes a plurality ofoptical beams including the particular portion of the plurality ofphotoemitter and photodetector pairs to detect the touch input.
 6. Thedevice of claim 1, including instructions executable by the processor tocause the processor to output the first optical beam pattern during theone-dimensional scan and the second optical beam pattern during thetwo-dimensional scan.
 7. The device of claim 1, including instructionsexecutable by the processor to cause the processor to perform thetwo-dimensional scan by outputting a first portion of the plurality ofoptical beams aligned along a first axis of the X-Y arrayed grid andoutputting a second portion of the plurality of optical beams alignedalong a second axis of the X-Y arrayed grid substantially perpendicularto the first axis.
 8. The device of claim 1, including instructionsexecutable by the processor to cause the processor to perform theone-dimensional scan by outputting a first portion of the plurality ofoptical beams aligned along a first axis of the X-Y arrayed grid andrefraining from outputting a second portion of the plurality of opticalbeams aligned along a second axis of the X-Y arrayed grid substantiallyperpendicular to the first axis.
 9. A non-transitory computer-readablemedium containing instructions executable by a processing resource tocause the processor to: monitor a touch-sensitive interface, using aplurality of photoemitter and photodetector pairs arranged around edgesof the touch-sensitive interface such that the plurality of photoemitterand photodetector pairs form a virtual X-Y arrayed grid overlaying thetouch-sensitive interface, for an occurrence of a touch input byperforming a two-dimensional scan of the touch-sensitive interface at afirst scan rate and at a first scan resolution; monitor, in response toa determination that no touch input occurrence is detected with thetwo-dimensional scan, the touch-sensitive interface for the occurrenceof the touch input by performing a one-dimensional scan of thetouch-sensitive input interface using a particular portion of theplurality of photoemitter and photodetector pairs and a first opticalbeam pattern at a second scan rate and at a second scan resolution;detect, during the one-dimensional scan, an occurrence of the touchinput and determine an X coordinate or a Y coordinate of the touch inputoccurrence on the virtual X-Y grid overlaying the touch-sensitiveinterface; switch, in response detecting the touch input occurrence bythe one-dimensional scan, back to monitoring the touch-sensitiveinterface by performing the two-dimensional scan using a second opticalbeam pattern different than the first optical beam pattern; collectmulti-axis coordinates of the touch input during the two-dimensionalscan; and utilize the multi-axis coordinates to perform an operationvisible on an associated graphical user interface.
 10. Thenon-transitory computer readable medium of claim 9, comprisinginstructions executable by a processing resource to: perform thetwo-dimensional scan by scanning the touch-sensitive interface along anx-axis of the virtual X-Y grid and along a y-axis of the virtual X-Ygrid perpendicular to the x-axis to determine an X-Y coordinate of thetouch input occurrence.
 11. The non-transitory computer readable mediumof claim 9, comprising instructions executable by a processing resourceto start, subsequent to the switch back to monitoring thetouch-sensitive interface by performing the two-dimensional scan, atimer, wherein the expiration of the timer without a detection of anintervening touch input occurrence triggers a switch back to monitoringthe touch-sensitive interface by performing the one-dimensional scan.12. The non-transitory computer readable medium of claim 11, wherein thetimer is a user-adjustable setting.
 13. A method comprising: detecting,using a plurality of photoemitter and photodetector pairs arrangedaround edges of a touch-sensitive interface such that the plurality ofphotoemitter and photodetector pairs form a virtual X-Y arrayed gridoverlaying the touch-sensitive interface, a touch input utilizing atwo-dimensional scan of the touch-sensitive interface at a first scanrate and at a first scan resolution using a first optical beam pattern;determining an X-Y coordinate of the touch input occurrence on thevirtual X-Y arrayed grid overlaying the touch-sensitive interface byscanning the touch-sensitive interface along an x-axis and along ay-axis perpendicular to the x-axis; collecting multi-axis coordinates ofthe touch input during the two-dimensional scan; utilizing themulti-axis coordinates to perform an operation visible on an associatedgraphical user interface; monitoring, utilizing the two-dimensionalscan, the touch-sensitive interface for an intervening occurrence of atouch input over a length of time; and switching, responsive to adetermination that no intervening occurrence of the touch input wasdetected over the length of time, to monitoring the touch-sensitiveinterface for an additional occurrence of the touch input by utilizing aone-dimensional scan using a second optical beam pattern different thanthe first optical beam pattern that includes a particular portion of theplurality of photoemitter and photo detector pairs at a second scan rateand at a second scan resolution.
 14. The method of claim 12, comprising:switching back to monitoring utilizing the two-dimensional scan inresponse to detecting the additional occurrence; and rescanning theadditional occurrence utilizing the two-dimensional scan.
 15. The methodof claim 13, comprising restarting the length of time for monitoringutilizing the two-dimensional scan in response to detecting theintervening occurrence of the touch input within the length of time.